Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/50—Shaping or impregnating by compression not applied for producing articles of indefinite length, e.g. prepregs, sheet moulding compounds [SMC] or cross moulding compounds [XMC]
  • B29C70/502—Shaping or impregnating by compression not applied for producing articles of indefinite length, e.g. prepregs, sheet moulding compounds [SMC] or cross moulding compounds [XMC] by first forming a mat composed of short fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/22—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length
  • B29C43/28—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of indefinite length incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/003—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor characterised by the choice of material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/32—Component parts, details or accessories; Auxiliary operations
  • B29C43/44—Compression means for making articles of indefinite length
  • B29C43/48—Endless belts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/06—Fibrous reinforcements only
  • B29C70/10—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres
  • B29C70/12—Fibrous reinforcements only characterised by the structure of fibrous reinforcements, e.g. hollow fibres using fibres of short length, e.g. in the form of a mat
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/04—Reinforcing macromolecular compounds with loose or coherent fibrous material
  • C08J5/0405—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres
  • C08J5/042—Reinforcing macromolecular compounds with loose or coherent fibrous material with inorganic fibres with carbon fibres
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
  • C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
  • C08J5/243—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using carbon fibres
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
  • B29K2101/12—Thermoplastic materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/08—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns
  • B29K2105/0854—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of continuous length, e.g. cords, rovings, mats, fabrics, strands or yarns in the form of a non-woven mat
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/06—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
  • B29K2105/12—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of short lengths, e.g. chopped filaments, staple fibres or bristles
  • B29K2105/14—Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts of short lengths, e.g. chopped filaments, staple fibres or bristles oriented
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2307/00—Use of elements other than metals as reinforcement
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2377/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers
  • C08J2377/02—Polyamides derived from omega-amino carboxylic acids or from lactams thereof
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
  • Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
  • Y10T428/2495—Thickness [relative or absolute]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/249921—Web or sheet containing structurally defined element or component
  • Y10T428/249924—Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
  • Y10T428/24994—Fiber embedded in or on the surface of a polymeric matrix
  • Y10T428/249948—Fiber is precoated

Definitions

• the present invention relates to a fiber-reinforced plastic and, more particularly, to an isotropic fiber-reinforced thermoplastic resin sheet and a process for the production thereof employing a chopped strand prepreg comprising a thermoplastic resin and a reinforcing fiber, and to a molded plate obtained from the sheet.
• thermosetting resin when this is made into a prepreg, there is a problem with storage management of the prepreg due to the short shelf life of the resin, and there are also the problems that the ability to follow product shape is poor, the molding time is long thus giving low productivity, etc.
• thermoplastic resin prepreg impact resistance is excellent when it is in a composite material, prepreg storage management is easy, the molding time is short, and there is a possibility of the molding cost being reduced.
• thermoplastic resin prepreg employing a thermoplastic resin as a matrix
• thermoplastic resin there are the following types from the viewpoint of the morphology of the reinforcing fiber and its orientation.
• a prepreg formed from a thermoplastic resin and a reinforcing continuous fiber that is a unidirectionally aligned fiber sheet or a woven/knitted fabric, formed using a continuous fiber.
• Such a prepreg has the advantage that the fiber volume fraction can be increased and has excellent performance in terms of modulus of elasticity and strength in the fiber axis direction.
• a prepreg has good flowability during molding, for example, flowability during stamping, and is suitable for producing moldings with various complicated shapes.
• the volume fraction of the reinforcing fiber cannot be made high.
• properties such as modulus of elasticity and strength are poor compared with one employing a continuous fiber.
• JP-A-9-155862 Patent Publication 1
• JP-A denotes a Japanese unexamined patent application publication
• Patent Publication 1 states that, in order to provide a fiber-reinforced thermoplastic resin sheet having a high weight fraction of a reinforcing fiber and good dispersion properties, for which the strength and the modulus of elasticity are pseudoisotropic within the plane and the flowability of the reinforcing fiber during post-processing is good, it is necessary to satisfy the following three requirements, that is, (1) the weight fraction of the reinforcing fiber is 50% to 85% and the weight fraction of the thermoplastic resin is 15% to 50%, (2) the average fiber length of the reinforcing fiber is 5 mm to 50 mm, and (3) the reinforcing fibers are dispersed non-directionally.
• Patent Publication 1 employs glass fiber in particular as the reinforcing fiber and has the object of increasing the weight fraction of the glass fiber, and does not propose one having excellent mechanical properties even with a low volume fraction of the reinforcing fiber.
• the invention according to Claim 1 of the present invention is an isotropic fiber-reinforced thermoplastic resin sheet wherein a chopped strand prepreg comprising a thermoplastic resin and a reinforcing fiber is layered so that the fiber orientation is random, the prepreg having a fiber volume fraction (Vf) of 20% to 50%, a length in the fiber axis direction of 15 to 45 mm, and a thickness of no greater than 0.13 mm, and the layered material is molded into sheet form by heating and pressing.
• Vf fiber volume fraction
• the invention according to Claim 3 which is another embodiment of the present invention, is a molded plate in which one or a layered plurality of the fiber-reinforced thermoplastic resin sheets according to Claim 1 are integrally molded, the theoretical number of layers of the plate satisfying the following expression.
• Theoretical number of layers (thickness of molded plate)/(thickness of one prepreg) ⁇ 10
• the invention according to Claim 5 is a process for the production of an isotropic fiber-reinforced thermoplastic resin sheet, the process comprising layering a chopped strand prepreg comprising a thermoplastic resin and a reinforcing fiber so that the fiber orientation is random, the prepreg having a fiber volume fraction (Vf) of 20% to 50%, a length in the fiber axis direction of 15 to 45 mm, and a thickness of no greater than 0.13 mm, and subsequently heating and pressing the layered material.
• Vf fiber volume fraction
• the fiber-reinforced thermoplastic resin sheet of the present invention and the molded plate obtained therefrom have excellent properties such as strength and modulus of elasticity, these properties being isotropic, compared with a conventional fiber-reinforced thermoplastic resin sheet and molded plate, since the reinforcing fiber is randomly dispersed within the plane even though the fiber volume fraction of the reinforcing fiber is low.
• ‘Isotropic’ in the present invention means that mechanical properties such as strength and modulus of elasticity do not vary with direction and are substantially uniform.
• the fiber-reinforced thermoplastic resin sheet of the present invention employs a chopped strand prepreg comprising a thermoplastic resin and a reinforcing fiber, the chopped strand prepreg being a small-piece prepreg in which unidirectionally aligned strands (fiber bundles) having the thermoplastic resin as a matrix are cut into a fiber length of, for example, on the order of 25 mm to 50 mm.
• the thermoplastic resin there can be cited one or more types of resins, etc.
• polypropylene polysulfone, polyether sulfone, polyether ketone, polyether ether ketone, aromatic or aliphatic polyamide, aromatic polyester, aromatic polycarbonate, polyether imide, polyarylene oxide, thermoplastic polyimide, polyamide imide, polybutylene terephthalate, polyethylene terephthalate, polyethylene, and acrylonitrile butadiene styrene.
• polypropylene polysulfone
• polyether ketone polyether ketone
• aromatic or aliphatic polyamide aromatic polyester, aromatic polycarbonate, polyether imide, polyarylene oxide, thermoplastic polyimide, polyamide imide, polybutylene terephthalate, polyethylene terephthalate, polyethylene, and acrylonitrile butadiene styrene.
• it may be used as a mixture in which part is a thermosetting resin.
• thermoplastic resins which have excellent heat resistance, modulus of elasticity, and chemical resistance, are particularly preferable.
• thermoplastic resins may contain colorants or various types of additives that are normally used.
• the prepreg of the present invention has a fiber volume fraction (Vf) of 20% to 50%, and preferably 20% to 45%, and the volume fraction of the thermoplastic resin is therefore 80% to 50%, and preferably 80% to 55%, the fiber content being rather low compared with a normal prepreg.
• Vf fiber volume fraction
• the fiber volume fraction (Vf) it is not desirable for the fiber volume fraction (Vf) to exceed 50% since, although values for mechanical properties increase, many voids, etc. are formed and the resulting fiber-reinforced thermoplastic resin sheet does not have uniform properties in some cases.
• the prepreg has a length in the fiber axis direction of 15 to 45 mm, and a thickness of no greater than 0.13 mm, and preferably no greater than 0.1 mm. It is not desirable for the length in the fiber axis direction of the prepreg to exceed 45 mm or for the thickness of the prepreg to exceed 0.13 mm since the isotropy of the resulting fiber-reinforced thermoplastic resin sheet is easily lost and high levels of properties cannot be obtained. Therefore, in the present invention, unless the volume fraction, the fiber length, and the thickness satisfy the above-mentioned requirements, a fiber-reinforced thermoplastic resin sheet that has adequate mechanical properties and that is isotropic cannot be obtained.
• the reinforcing fiber that can be used in the present invention is an inorganic fiber, an organic fiber, a metal fiber, or a fiber formed from a mixture thereof.
• the inorganic fiber include carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, tungsten carbide fiber, boron fiber, and glass fiber.
• the organic fiber include aramid fiber, high density polyethylene fiber and, in addition, normal nylon and polyester fibers.
• the metal fiber a fiber made of stainless steel, iron, etc. may be used, and there is also carbon fiber, etc. coated with a metal. It is particularly preferable to use carbon fiber. In the case of carbon fiber, it is preferable to use strands of 800 to 1600 tex with 12 K to 24 K filaments.
• the chopped strand prepreg of the present invention is obtained by paralleling strands (fiber bundles) of a reinforcing fiber so that the thickness is no greater than 0.13 mm, subsequently applying a thermoplastic resin to the paralleled fiber bundles so that the fiber volume fraction (Vf) is in the range of 20% to 50%, and cutting the fiber-reinforced thermoplastic resin sheet thus formed so that, with respect to the longitudinal direction, the width is as desired, preferably 10 to 30 mm, and the length in the fiber axis direction is in the range of 15 to 45 mm.
• the strands of reinforcing fiber may be untwisted or twisted, but when paralleling, the strands preferably have the fibers spread as far as possible.
• a method for applying the thermoplastic resin is not particularly limited.
• a method in which strands of reinforcing fiber are directly impregnated with a molten thermoplastic resin a method in which a film-form thermoplastic resin is melted and strands of reinforcing fiber are impregnated therewith, and a method in which a powdered thermoplastic resin is melted and strands of reinforcing fiber is impregnated therewith.
• the method for cutting the strands of reinforcing fiber impregnated with the resin is not particularly limited, but a pelletizer or a cutter of the guillotine type or the Kodak type may be used.
• the chopped strand prepreg thus obtained is uniformly deposited/layered so the orientation of fibers is random.
• a method for uniformly depositing/layering the chopped strand prepreg randomly there can be considered, for example in the case of continuous production, a method in which a prepreg obtained by cutting is made to fall under gravity directly from a high position and deposited on a belt conveyor with a steel belt, etc., a method in which air is blown into the path of fall or a baffle plate is mounted therein, etc.
• a method in which a cut prepreg is stored in a container, a transport system is mounted on a lower face of the container, and the prepreg is distributed to a mold, etc. for sheet production can be considered.
• this layered material is subjected to heating and pressing by, for example, passing it together with the steel belt between hot rolls, or to interval pressing to thus melt the thermoplastic resin and integrate it with the reinforcing fiber, thereby giving an isotropic fiber-reinforced thermoplastic resin sheet.
• a method for carrying out the integration in addition to the above, there can be considered, for example, a method in which heating and cooling is continuously carried out by a belt press, a method in which, after preheating is carried out by a far-infrared heater, cold pressing is carried out, or a batch method in which a heating and cooling press is used.
• the chopped strand prepreg is layered on a steel belt so that the orientation of fibers is random, and the layered material is then subjected to a heating/pressing treatment at 150° C. to 400° C. and 0.1 to 10 MPa using a double belt press, an interval hot press, or a hot roll.
• CV value for the flexural strength and the flexural modulus of elasticity measured in accordance with JIS K 7017 of no greater than 10 are particularly preferable.
• the CV value referred to here is an indicator showing the relative scatter (coefficient of variation) and is a value expressed by (standard deviation/average measurement) ⁇ 100(%); the smaller this value the higher the precision of the measurement.
• Measurement of the fiber volume fraction was carried out in accordance with JIS K 7075.
• Measurement of the flexural strength and the flexural modulus of elasticity was carried out in accordance with JIS K 7017.
• the property retention (%) is a value expressed by (property value at 80° C./property value at room temperature) ⁇ 100.
• PA6 film (nylon 6, manufactured by UNITIKA Ltd., weight per unit area 28.75 g/m 2 ) was placed on both sides of a carbon fiber strand sheet form material having a weight per unit area of 40 g/m 2 in which continuous fibers formed from HTA-12K carbon fiber (800 tex, strands with 12,000 filaments, manufactured by TOHO TENAX Co., Ltd.) were oriented in one direction, thus giving a sandwich-like layered material in which the sheet form material was held between the films.
• This layered material was heated at 230° C. to 260° C. to thus impregnated the sheet form material with molten PA6 film.
• the thickness of the resin-impregnated sheet form material thus obtained was 0.07 to 0.08 mm.
• the fiber volume fraction was 30%.
• thermoplastic resin sheet thus obtained was preheated at 260° C. to 280° C. by a far-infrared heater, it was subjected to a heating/pressing treatment at 80° C. to 120° C. and 40 to 50 MPa by a die press method, thus giving a molded plate of the present invention having a plate thickness of 2.3 mm (theoretical number of layers 28).
• the mechanical properties of this molded plate were as shown in Table 1.
• PA6 film (nylon 6, manufactured by UNITIKA Ltd., weight per unit area 28.75 g/m 2 ) was placed on both sides of a carbon fiber strand sheet form material having a weight per unit area of 80 g/m 2 in which continuous fibers formed from HTA-6K carbon fiber (400 tex, strands with 6,000 filaments, manufactured by TOHO TENAX Co., Ltd.) were oriented in one direction, thus giving a sandwich-like layered material in which the sheet form material was held between the films. This layered material was heated at 260° C. to thus impregnated the sheet form material with molten PA6 film.
• the resin-impregnated sheet form material thus obtained had a width of about 5 mm and a thickness of 0.26 mm (fiber volume fraction 50%).
• the treatments thereafter were carried out in the same manner as in Example 1, a fiber-reinforced thermoplastic resin sheet was prepared using a strand prepreg having a cut length of 25 mm and a width of 5 mm, and a molded plate having a thickness of 2.3 mm (theoretical number of layers 9) was obtained using the sheet.
• the mechanical properties of this molded plate were as shown in Table 1.
• Example 2 The resin-impregnated sheet form material (width 20 mm) obtained in Example 1 was cut into three different lengths of 10 mm (Comparative Example 2), 40 mm (Example 2), and 50 mm (Comparative Example 3), and molded plates were produced therefrom in the same manner as in Example 1.
• the mechanical properties thereof were as shown in Table 1.
• the length of the prepreg was 10 mm, which is short, (Comparative Example 2, outside the scope of the present invention)
• the mechanical properties of the molded plate, and in particular the flexural strength were poor.
• Example 4 the weight per unit area of the PA6 film was changed so as to adjust the fiber volume fraction of the prepreg to 15% (Comparative Example 4) and 45% (Example 3). Molded plates were molded in the same manner as in Example 1 using the prepregs obtained. The mechanical properties thereof were as shown in Table 1. It can be seen that one with a fiber volume fraction of 15% (Comparative Example 4, outside the scope of the present invention) did not have sufficient mechanical properties.
• Example 5 the weight per unit area of the sheet form material and the weight per unit area of the PA6 film were changed so as to adjust the fiber volume fraction of the prepreg to 30%, and prepregs having a thickness of 0.15 mm (Comparative Example 5), 0.10 mm (Example 4), and 0.05 mm (Example 5) were obtained.
• a thickness of 0.15 mm the weight per unit area of the sheet form material was adjusted to 80 g/m 2
• the weight per unit area of the PA6 film was adjusted to 57.5 g/m 2 .
• Molded plates were produced in the same manner as in Example 1 using the prepregs thus obtained. The mechanical properties thereof were as shown in Table 1.
• This comparative example was a case in which a molded plate was produced using a normal carbon fiber nonwoven fabric instead of the chopped strand prepreg.
• a carbon fiber-reinforced stampable sheet in which an HTA-12K carbon fiber nonwoven fabric (800 tex, strand with 12,000 filaments, manufactured by TOHO TENAX Co., Ltd.) and PA6 had been integrated was preheated at 260° C. to 280° C. by a far-infrared heater, it was subjected to a heating/pressing treatment at 80° C. to 120° C. by a die press method, thus giving a 3 mm thick molded plate.
• the mechanical properties thereof were as shown in Table 1. It can be seen that the fiber volume fraction was the same as that of Example 1 of the present invention, but the values for the mechanical properties were better for those of the present invention.
• a 3 mm thick molded plate was produced by standard injection molding using, instead of the chopped strand prepreg, a chopped fiber (length 6 mm) of the same carbon fiber as in Example 1 and PA6 resin pellets.
• the mechanical properties of the molded plate thus obtained were as shown in Table 1. It can be seen that the fiber volume fraction was the same as that of Example 1 of the present invention, but the values for the mechanical properties were better for those of the present invention.
• the fiber-reinforced thermoplastic resin sheet of the present invention and the molded plate obtained therefrom have excellent properties such as strength and modulus of elasticity and, moreover, since these properties are isotropic, they are suitable as materials for molding FRP moldings with various shapes.

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• Chemical & Material Sciences (AREA)
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• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Inorganic Chemistry (AREA)
• Composite Materials (AREA)
• Textile Engineering (AREA)
• Reinforced Plastic Materials (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)

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• 2006
  • 2006-08-14 WO PCT/JP2006/315999 patent/WO2007020910A1/ja not_active Ceased
  • 2006-08-14 CN CN2006800300584A patent/CN101243121B/zh active Active
  • 2006-08-14 JP JP2007530990A patent/JP4789940B2/ja active Active
  • 2006-08-14 EP EP06796389A patent/EP1927618A4/en not_active Withdrawn
  • 2006-08-14 US US12/063,191 patent/US9545760B2/en active Active
  • 2006-08-14 KR KR1020087002387A patent/KR100944032B1/ko not_active Expired - Fee Related

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